1) Field of the Invention
The present invention relates to membrane-type closures for product containers.
2) Description of Related Art
Conventional containers for snack foods and other products often have a membrane closure sealed to a top rim of the container and an overcap covering the membrane. The container is initially opened by the consumer by removing and discarding the membrane. Typically, the membrane includes an outwardly projecting tab to aid in the removal of the membrane. The overcap is provided to allow the consumer to re-close the container once the membrane is removed.
In addition to re-closing the container, the overcap is beneficial to the manufacturer and packager of the container. For example, the overcap prevents dust, grease, and other containments from collecting on the container's top membrane closure during the manufacturing and packaging operations. Also, the overcap effectively holds down the tab of the membrane closure against the container and reduces the probability of the tab getting caught or damaged on the equipment during the manufacturing and packaging operations.
Specifically, the membrane closure and the tab are usually cut from a membrane web material as a single piece. The membrane closure is sealed to the container with the tab extending horizontally off the side of the container. When the overcap is applied, the skirt of the overcap engages and pushes the tab down and along the side of the container, where the tab is less likely to get caught or damaged.
However, in order to engage and push the tab down, the overcap must overcome the additional material from the tab along the container bead, which adds to the difficulties of the overcap application process. Also, in some applications, an overcap adds little to no value for the consumer. For example, in a single-serving container the overcap is discarded with the membrane closure after the initial opening because there is no need to use the overcap to reclose the container. In such applications, it would beneficial to eliminate the overcap. However, as mentioned above, without the overcap the tab of the membrane closure is more likely to interfere with the manufacturing and packaging operations.
Alternative methods of securing or handling the tab have been considered. For example, the tab may be folded back and heat sealed to the rest of the membrane closure or a material may be used for the membrane closure and tab that allows for the tab to be folded into place (i.e., dead fold retention) either against the rest of the membrane closure or along the side of the container. However, these methods add excessive cost or complexity to the operations.
In light of the foregoing there remains a need to provide a sealable membrane closure for containers that alleviates the need of an overcap to prevent the collection of containments onto the membrane closure or to secure the removal means of the membrane closure, i.e. the tab, into a safer position. As always, it would be beneficial for such a membrane closure to be cost-effective and simple to produce.